Presently, there exist a number of machines that perform the function of inserting envelopes, manipulating garbage bags for packaging, and generally for transferring items on a machine from one location on the machine to other locations on the machine.
Many of the envelope inserting machines have the capacity for performing the functions of separating inserts from a stack, opening the envelopes, inserting mailing inserts inside the envelopes, putting pre-determined printed matter on the envelopes, and sealing the envelopes. Having a machine that can perform all these functions can be very beneficial to the user, especially for the user having a large capacity of mailings to be mailed.
However, one major disadvantage of using this type of machine is the time and expense used to repair and service the machines. Specific functioning components on the mail inserter machine which require substantial time and cost to repair and service include the front table cam shaft, the upper drive shaft, and the main drive system.
The front table cam shaft is a continuous rotating shaft fitted with individually adjustable cams. Each cam on the shaft controls a separate function in the machine. For example, the cams may operate a stacker for stacking envelopes, a flap closer for closing the flaps of envelopes, a sucker bar for moving suction cups which adhere to the envelopes, and jaw openers used to grip the envelopes. Of course additional cams can exist on the front table cam shaft for performing additional functions. During the manufacturing of a front table, the installation of the cam shaft requires that bearing assemblies be bolted onto the table, and then a line reamer is run through the bearing blocks. Each bearing block has an individual bushing pressed therein. The reamer opens the bushings inside diameter to the equivalent size of the outside diameter of the cam shaft. The bushings are approximately in line with each other prior to reaming. Line reaming will match and line up the bushings inside diameter exactly. Once the bearing blocks are line reamed they can not be replaced individually without extensive time and effort. One bushing may be reamed slightly higher or lower than another bushing, while another may be further forward on the table than other bushings. If one bearing block bushing wears out because of extensive machine use or lack of lubrication before others, the individual block bearing bushing may not have to be replaced but can be line reamed. Line reamers are usually not available in the field therefore a hand reamer would be used. Shimming the bearing block would be required. Occasionally, bushing is reamed oversized deliberately to cut down on a lengthy repair process. This is not good practice and will result in repeat bushing failure. Once the bearing blocks are line reamed assembly of the front table can begin. Installation of the cam shaft along with mounting and all the cams, collars, sprockets, and gears onto the shaft is first, everything else is attached on top or along side of the cam shaft. Replacing a cam shaft can be strenuous and time consuming. To replace a cam shaft, the shaft has to be rotated to loosen all the set screws attached within the cams and components mounted on the shaft. The cams and components are moved sideways along the shaft to allow set screw burr marks to be removed by filing to enable components to be removed from the shaft. Sometimes the cam shaft is bent to the extent that the shaft can not be rotated. The shaft is driven by a sprocket keyed to the shaft. Keys are usually drilled, pinned and fitted to the cam shaft for rotating the cam shaft. If the cam shaft bends it usually bends where the sliding sprocket is, and the key is usually bent as well. Sometimes a damaged cam shaft has to be cut in half to be removed. Clearance for using a hack saw or the like to cut the shaft and gain access to the non-turning cam shaft and set screws requires extensive time to remove the front table top plate and many other attached parts. Removal of the bearing block mounting bolts, sprocket guide and drive chains must also be completed before removing the cam shaft. This removal process takes a number of hours. Users of the mail inserter machine usually cannot afford lengthy repairs and down-time necessary for repairing or replacing an individual bushing mounted on the front table around the shaft.
Another problem area on inserter machine requiring substantial time and cost to service and repair is a rotatable upper drive shaft. This shaft has a round diameter and has mounted therearound a number or bearings and bearing blocks supporting and aligning the shaft. The shaft also has a keyway slot therein for a sliding bevel gear assembly. Present manufacturing of the sliding bevel gear include a key which is fastened to the inside key way of the bevel gear. In operation, as the shaft rotates, the shaft aligns itself within the supporting bearing blocks. In aligning within the bearing blocks, the shaft places concentrated loads on the bearing blocks supporting it. This aligning causes the concentrated loadings on the bearing blocks to eventually wear on the supporting bearings inside the bearing blocks, thereby creating a need to replace the worn bearings. To replace the worn bearings, the bearing block or blocks containing the worn bearings must be removed from the table it is mounted upon. Since the shaft is one continuous elongated member, when removing one bearing block to replace the bearing inside, the bearing block must be detached from the supporting table and slid off the end of the shaft to allow the bearing block. On the lower cam shaft, several blocks may have to be removed to get to the worn block. Conversely, when replacing the new or repaired bearing blocks back onto the table and shaft, the other bearing blocks must also be positioned back on the shaft and mounted back onto the supporting table. When remounting the bearing blocks, extensive time must be taken to align the bearing blocks with the shaft for effective and efficient rotation of the cam shaft.
A third component of the mail inserter machine requiring substantial time and cost to service and repair is the main belt drive system which drives the mechanisms of the machine. In present envelope inserter machines, the main drive systems transfer the driving force from a drive motor to a prior art speed reducer via a drive belt. Output drive from the prior art speed reducer is used to transfer rotational force to both a cam indexing box and to a cam shaft via drive chains. During operation, the prior art drive chains stretch, sprockets wear, and eventually require replacement. As the chains stretch, tension and timing functions may require occasional readjustment to compensate for the stretching (or chain/sprocket wear). The prior art cam indexing box drives the indexing portion of the inserter via a ring and pinion gear 3-to-1 drive configuration. The ring and pinion gear are aligned, and corresponding bearing posts are pinned to avoid change in alignment. This alignment process is service intensive and time consuming